The present invention relates to generation of test inputs for gyros.
BACKGROUND OF THE INVENTION
The gyros are installed on the platform, which is used to provide information
pertaining to the angle at which aircraft is flying. The gyros are meant for stabilizing the
platform (Zero position). Once the platform is stabilized, the electrical force applied to the
gyro is used to calculate the angle at which the aircraft is flying. Two gyros are used, one
meant for X-axis and the other one for Y-axis.
The automatic test bench for gyros (ATP) is meant for carrying out the final
acceptance test for the gyros in the stand-alone mode. It is a PC based test set up
incorporating standard and custom built test and measuring instruments interfaced by
GPIB bus.
The test bench basically contains two 19” racks of height 38U containing standard
equipments, equipment and interconnection trays, gyro servo related hardware and
interconnecting looms.
SUMMARY OF PRESENT INVENTION
In accordance with one aspect of present invention is to provide capabilities to the
gyros system as installed on the platform, which is used to generate trajectories
pertaining to the angle at which aircraft is flying.
In accordance with second aspect of present invention is to provide the automatic
test bench for gyros (ATP) for carrying out the final acceptance test for the gyros in the
stand-alone mode. It is a PC based test set-up incorporating standard and custom built
test and measuring instruments interfaced by GPIB bus.
In accordance with another aspect of present invention is to maintain the
temperature of the Gyro base, the Gyro cover and the Gyro at around 80 deg C, two
transformers installed in the heating tray provide voltages for the heating elements.
In accordance with yet another aspect of present invention is the test bench
basically contains two 19” racks of height 38U containing standard equipments,
equipment and interconnection trays, gyro servo related hardware and interconnecting
looms.
In accordance with yet another aspect of present invention, the subject invention
is easy to repair & maintain.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become more apparent
and descriptive in the description when considered together with figures presented:
Fig. 1 is a Rack arrangement for the Gyro-ATP test bench
Fig. 2 is a System Level Block Diagram
Fig. 3 is a Block diagram of Temperature Control Tray
Fig. 4 is a Block diagram of Servo Tray
Fig. 5 is a Front Panel view of Heating Tray
Fig. 6 is a Front Panel view of General Power Supply
DETAILED DESCRIPTION
The gyros are installed on the platform, which is used to provide information
pertaining to the angle at which aircraft is flying. The gyros are meant for stabilizing the
platform (Zero position). Once the platform is stabilized, the electrical force applied to the
gyro is used to calculate the angle at which the aircraft is flying. Two gyros are used, one
meant for X-axis and the other one for Y-axis.
The automatic test bench for gyros (ATP) is meant for carrying out the final
acceptance test for the gyros in the stand-alone mode. It is a PC based test set-up
incorporating standard and custom built test and measuring instruments interfaced by
GPIB bus.
The Block diagram shows gyro unit under test interfaced to measuring and testing
instruments through a Servo tray, which consists of 9 PCBs. The servo tray provides
excitation, wheel supply and temperature control outputs to the gyro unit. The servo tray
is interfaced to industrial PC through buffer card. In order to maintain the temperature of
the Gyro base, the Gyro cover and the Gyro at around 80 deg C, two transformers
installed in the heating tray provide voltages for the heating elements. The temperature
of the elements is sensed through temperature probe and maintained through servo loop
(by switching the heater on and off, based on the temperature) through the temperature
control module mounted on the front panel of the temperature tray.
The Servo tray takes the inputs like X- axis and Y- axis current sources and
provides X–axis and Y--axis outputs to the Channel Card X and Y as Pickoff X and
Pickoff Y. The Channel cards demodulate the signal from the Gyro and the outputs are
filtered. The detailed description of each card used in the servo tray is explained below.
The current sources are required to provide current compensation to the gyro. The
instruments like oscilloscope, DMM, are connected to PC through GPIB bus.
Annexure‐II
FUNCTIONAL DESCRIPTION
This acceptance test to be carried out the methods to be used & the result to be
obtained for the Automatic Gyro Acceptance Test Bench. (Refer Fig. 1)
The interconnection of the all module is defined in the level system block diagram
(Refer Fig. 2).
1. Ventilation Tray: This tray has fans inside it to provide a cooling effect to the servo
tray. It also has the ON/OFF control to switch ON and OFF the test bench, an AC Lamp
indicator and an emergency push button.
2. Temperature Control Tray: This tray holds two temperature controllers which
controls the temperature of the GYRO COVER, GYRO BASE and the GYRO. The
normal temperature of the gyro cover and base are maintained at 80°C. The two
Microprocessor based temperature controllers sense the temperature of the gyro cover
and base through feedback mechanism and these Controllers turn ON or OFF the relays
so as to maintain the temperatures at the required level. This tray has test points on the
front panel to allow users to check the corresponding outputs. (Refer Fig. 3)
3. Oscilloscope Tray: This tray holds the 100 MHz Oscilloscope. This oscilloscope is a
two channel scope, one for X axis and the other for Y axis. The oscilloscope gets input
from the servo tray and displays the corresponding.
4. Servo Tray: The Servo tray is the heart of the Acceptance Test Bench. It receives
input from the Gyro and the outputs are viewed through instruments like the DMM,
DAVM, Oscilloscope and the Industrial PC. This tray consists of nine cards as mentioned
below and each card is explained along with block diagram. The Servo Tray also consists
of the motherboard which acts as an interface between the below mentioned cards, to the
external connectors made available at the rear end of the tray and also to the test points
and LED’s in the front panel of the Servo tray. (Refer fig. 4)
The Servo tray consists the following modules:
- Servitude card I
- Servitude card II:
- X and Y Channel Cards:
- Demodulator Filter Card:
- Measuring Filter Card:
- Relay card 1:
- Relay card 2:
- Relay card 3:
- Mother Board:
Annexure‐II
11. Heating Tray: This tray consists of two auto transformers of specification
INPUT=220VAC OUTPUT=0 -270VAC LOAD=63VA. The outputs of these transformers
are taken to the relays in the temperature control tray through which they are passed on
to the heating elements available in the Gyro cover and base. (Refer Fig. 5)
12. General Power Supply Tray: It Contain one PCB, front panel with switch for
auto/manual, fuse and power supply test points. It has the Thermal Fuse, which indicates
the serviceability of the system. (Refer Fig. 6)

WE CLAIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and is for the purpose of teaching those skilled in the art of the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications which are within the scope of the appended claims is reserved. We Claim

1. The Gyro ATP Test Bench, comprising
- Two 19” & 38U racks for housing the various equipments,
- Ventilation Tray,
- Temperature Control Tray,
- Oscilloscope Tray,
- Servo Tray,
- Heating Tray,
- General Power Supply Tray,
- A generic computing device with display & atleast one interface card like GPIB,
- Generic equipments capable of monitoring of waveforms, frequency, voltage etc. &
- Looms & Cables for interconnecting Unit under test and various equipments of the said bench as well as the generic computing device.

and as described earlier in the detailed description.

2. The system as per claim 1, capable of generation of atleast one flight trajectory for testing of unit under test containing atleast one gyros installed, said system capable of uploading atleast one flight trajectory using generic computing device.

3. The system as per claim 1, capable of controlling temperature in closed loop to thermally stabilize various components of Unit under test using automated intelligent circuitry, upto 180degC.

4. The system as per claim 1, capable of generating different frequencies upto 400KHz with different amplitudes and shapes.

5. The system as per claim 1, capable to cool the said test bench using suitable number of fans.

6. The system as per claim 1, capable of selection of different relay components based on the type of input fed by user using generic computing device or automatically in case a trajectory is selected.

7. The system as per claim 1, capable to measure the outputs at the time constants of 6 seconds.
,TagSPECI:As per Annexure-II